BASE ISOLATION

An innovative approach for

earthquake safe structures

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Page 1

What is base isolation ?

# Base isolation, also known as seismicisolation system, is a collection ofstructuralelementswhichshouldsubstantially decouple a superstructurefrom its substructure resting on a shakingground thus protecting the buildingsstructural integrity.# It is the most powerful tool of theearthquake engineering pertaining to thepassivestructuralvibrationcontroltechnologies.Free Powerpoint Templates

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(Top Mounting Plate Not Shown)

Energy Dissipation Core

Cover Rubber

Steel Reinforcing Plates

Internal Rubber Layers

Bottom MountingPlate

Seismic IsolatorFree Powerpoint Templates

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Friction Pendulum Bearing

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Base Isolation System using Spherical Sliding

Isolation SystemFree Powerpoint Templates

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Base Isolation System using Elastomeric

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Goals of base isolation

Protection of Life Current Code Additional Benefits of IsolationProtection of Building FrameProtection of Non-Structural Componentsand ContentsProvide for an operational facility after theearthquakeProtection of Processes and Function

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Foundation constructed on layers of timber

PowerpointTemplatesPage 8inFreetraditionalbuildings

Typical Base Isolation in Modern Buildings

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San Francisco Airport International Terminal

Worlds Largest Isolated Building

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Applications of Base Isolation

1st application in New Zealand in19741st US application in 19841st Japanese application in 1985US - 80 buildings and 150bridgesJapan - 1000 buildings and 500bridgesNepal Not recorded yetFree Powerpoint Templates

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Earthquakenot isolated isolated

Movement of Building with Base

Isolation vs. No Base IsolationFree Powerpoint Templates

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Forces reduced by 3 to6 across the isolatorsForces reduced by 8 to12 at the roof

Isolated Structure

Ground Forces are

amplified by a factor of 3to 4 at the roof.

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Conventional Structure

Forces reduced by 3 to6 across the isolatorsForces reduced by 8 to12 at the roof

Isolated Structure

Ground Forces are

amplified by a factor of 3to 4 at the roof.

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Conventional Structure

Forces reduced by 3 to6 across the isolatorsForces reduced by 8 to12 at the roof

Isolated Structure

Ground Forces are

amplified by a factor of 3to 4 at the roof.

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Conventional Structure

advantages of base Isolation

# Base Isolation is meant to enable a buildingor non-building structure to survive apotentially devastating seismic impactthrough a proper initial design or subsequentmodifications(retrofit).# The application of this technique can raise astructure's seismic performance and itsseismic sustainability considerably.# It provides the design profession the ability todesign a building that is operational after amajor earthquake.

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Benefits ofSeismic Isolation Retrofit Work maybe Confined toBasement Building Can Continue to beOccupied Often the Most EconomicSolutionFree Powerpoint Templates

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ConclusionsBase isolation provides the highestlevel of protection operational after a major earthquake.Base isolation has significantbenefits for the earthquakeprotection of historic structures.Free Powerpoint Templates